Host bus adapter with multiple hosts

Abstract

A multi-host host bus adapter (HBA) can be connected to multiple host devices to allow the multiple host devices to communicate on a SAN fabric. More specifically, the multi-host HBA provides an interface for multiple SAN hosts without necessitating an HBA on each host, eliminating the need for an on-board HBA on each SAN host. The multi-host HBA interfaces to memory in each SAN host to which it is connected using PCI-Express (or a similar protocol), and communicates with other devices on the SAN fabric using Fibre Channel ports. The multi-host HBA communicates by receiving a command from a connected host, forwarding the command to a processor in the multi-host HBA, and sending the command to a device on a SAN. When the multi-host HBA receives a response from the device on the SAN, the multi-host HBA associates the response with the process and sends the response to the host.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]Embodiments according to the invention relates to blade servers. More particularly, embodiments according to the invention relate to connecting multiple blades to a single host bus adapter in a blade chassis.[0003]2. Description of the Related Art[0004]Effectively deploying multiple devices in a network environment becomes an increasingly complex task as transmission data rates, processor speeds, and storage capacities increase. Storage area networks (SANs) have been developed as specialized high-speed networks, referred to as fabrics, to connect computer systems, control software, and storage devices over the fabric. SANs typically allow block level input / output (I / O) rather than file-level access. Thus, every device connected to a SAN fabric appears as a locally attached device to other devices on the fabric.[0005]Although a SAN allows for relatively simple interchangeability of components without disrupting other com...

AI Technical Summary

Benefits of technology

[0008]A host bus adapter (HBA) according to one or more embodiments of the invention can be connected to multiple host devices. More specifically, a multi-host HBA according to one or more embodiments of the invention provides an interface for multiple SAN hosts to a SAN fabric using PCI Express to Fibre channel ports without necessitating an HBA on each host. The multi-host HBA interfaces directly to a bridge in each SAN host to which it is connected. The multi-host HBA operates by processing a received command from a connected SAN host, forwarding the command to a processor in the multi-host HBA, and sending the command to a device on the SAN fabric. When the multi-host HBA receives a response from the device on the SAN fabric, the multi-host HBA associates the response with the process command and sends the response to the host.

Problems solved by technology

Effectively deploying multiple devices in a network environment becomes an increasingly complex task as transmission data rates, processor speeds, and storage capacities increase.

Although a SAN allows for relatively simple interchangeability of components without disrupting other components, physical space available for components also presents a challenge.

However, the actual data throughput on each of these HBAs is typically quite small compared to the capacity and link speeds that are possible in modern networks.

In other words, a modern server typically cannot saturate its on-board HBA.

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